阅读说明：本技术 一种气载核素环境迁移试验中c-14、h-3投源装置和方法 (C-14 and H-3 source projection device and method in airborne nuclide environment migration test ) 是由 韩宝华 原寒 曹俏 张超 张晟 李建国 贡文静 王慧娟 马炳辉 于 2021-07-30 设计创作，主要内容包括：本发明公开了一种气载核素环境迁移试验中～(14)C、～(3)H投源装置和方法,装置包括：～(14)CO-(2)的投源装置和氚化水的投源装置,～(14)CO-(2)的投源装置包括CO-(2)反应器、密封实验舱和CO-(2)吸收器；氚化水的投源装置包括氚化水发生器、密封实验舱和氚吸收器；整个实验装置均放置在高照度人工气候室,自动设置光照、温度、湿度,间接控制密封实验舱的实验参数,核素转移实验结束后,密封实验舱的放射性尾气通过高照度人工气候室的高效通风过滤系统过滤,达标排放。本发明在模拟后处理厂气态流出物中的关键核素氚和14C化学形态及排放源项特征,设计改进了针对气载核素氚和14C生态环境迁移试验舱的投源方法和装置,保证了氚和14C在多种农作物生态转移研究试验的顺利开展。(The invention discloses a method for testing migration of airborne nuclide in environment 14 C、 3 H source device and method, the device includes: 14 CO 2 a source device of the tritiated water and a source device of the tritiated water, 14 CO 2 the source device comprises CO 2 Reactor, sealed experiment chamber and CO 2 An absorber; the tritiated water feeding device comprises a tritiated water generator, a sealed experiment cabin and a tritium absorber; the whole experimental device is placed in a high-illumination artificial climate chamber, illumination, temperature and humidity are automatically set, experimental parameters of the sealed experimental chamber are indirectly controlled, and after the nuclide transfer experiment is finished, radioactive tail gas of the sealed experimental chamber passes through the high-illumination artificial climate chamberThe high-efficiency ventilation and filtration system filters and discharges after reaching the standard. According to the invention, the chemical forms and emission source item characteristics of the key nuclides tritium and 14C in the gaseous effluent of the post-simulation treatment plant are designed and improved, and the source throwing method and device for the ecological environment migration test chamber of the airborne nuclides tritium and 14C are designed and improved, so that the tritium and 14C can be smoothly developed in ecological transfer research tests of various crops.)

1. Airborne nuclide environmental migration test¹⁴C、³H device of throwing source, its characterized in that includes:¹⁴CO₂a source device of the tritiated water and a source device of the tritiated water,

the above-mentioned¹⁴CO₂The source device comprises CO₂Reactor, sealed experiment chamber and CO₂An absorber;

will be provided with¹⁴Transfer of radioactive source C to the CO₂In the reactor, CO is produced by reaction₂The generated gas is loaded into a sealed experiment chamber to carry out gas-loading nuclide¹⁴Ecological transfer test of C in crops, airborne nuclide¹⁴C, after the crops are polluted for a first preset time, opening the sealed experiment chamber, and allowing radioactive tail gas to pass through the CO₂Discharging the waste gas after the absorber;

the tritiated water feeding device comprises a tritiated water generator, a sealed experiment cabin and a tritium absorber;

will be provided with³Transferring the radioactive source liquid to the tritiated water generator, reacting to generate tritiated water, and spraying the generated tritiated water into the sealed experiment chamber to carry out gas-borne nuclide³Ecological transfer experiment of H in crops, airborne nuclide³After H is polluted in crops for a second preset time, opening the sealed experiment chamber, and discharging radioactive tail gas after the radioactive tail gas passes through the tritium absorber;

wherein, whole experimental apparatus all places in high illumination artificial climate room, sets up illumination, temperature, humidity automatically, and the experimental parameters of the sealed laboratory of indirect control, after nuclide transfer experiment, the radioactive tail gas of sealed laboratory filters through the high-efficient ventilation filtration system of high illumination artificial climate room, and discharge to reach standard.

2. The device of claim 1, wherein the frame of the sealed experimental chamber is made of bridge-cut aluminum, and the four sides and the top of the frame are made of transparent glass with a volume of 11m³Bottom area of 5m²。

3. The apparatus of claim 1, wherein the CO is present in a gas phase₂The reactor is a 500ml distillation flask, wherein 0.2mol/L Na is quantitatively added into one bottle mouth₂CO₃Solutions and¹⁴c radioactive source solution, 0.2mol/L H is added in a quantitative manner₂SO₄A magnetic stirrer is arranged at the bottom of the distillation flask, radioactive gas is generated at the other bottle mouth, and the gas is loaded into the first sealed experiment chamber through a polyethylene pipe to carry out gas loading of nuclides¹⁴And C, testing ecological transfer parameters of crops.

4. The apparatus of claim 1, wherein the CO is present in a gas phase₂The absorber is a 500ml conical flask, and after the airborne nuclide ecological transfer test is finished, the radioactive tail gas discharged by the first sealed test chamber is absorbed by adopting a saturated NaOH solution.

5. The device as claimed in claim 1, wherein the tritiated water generator is a compressed air type atomizer, the median diameter of mist particles is 3.9 μm ± 25%, the ratio of mist particles with the diameter less than 5 μm is > 65%, the maximum atomization rate is not less than 0.2ml/min, the pressure range is 0.08-0.15 MPa, and the free air flow rate of a compression pump is not less than 10L/min.

6. The apparatus of any one of claims 1 to 5, wherein the tritium absorber employs a color-changing silica gel to absorb the radioactive off-gas.

7. Airborne nuclide environmental migration test¹⁴C、³The H-sourcing method applied to the device of any one of claims 1 to 6, comprising:¹⁴CO₂the method for feeding tritiated water and the method for feeding tritiated water,

(1) the above-mentioned¹⁴CO₂The source casting method comprises the following steps:

(1.1) placing typical crops near a plant site in a sealed experiment cabin;

(1.2) suction with a liquid-feeding gun of 5.5X 10⁴Bq/ml ¹⁴4.5ml of radioactive source solution of C was transferred to CO₂In the reactor, 10ml of 0.2mol/L Na was added₂CO₃Adding 12ml of 0.2mol/L sulfuric acid solution into the solution, reacting to generate CO2, magnetically stirring, and carrying gas into a sealed experiment chamber through a polyethylene tube to carry out gas-carried nuclide¹⁴C in the crop ecological transfer experiment and sealed experiment cabin¹⁴Total activity of C2.5X 10⁵Bq, activity concentration in air 2.2X 10⁴Bq/m³；

(1.3) airborne nuclides¹⁴C, after 24 hours of pollution in crops, opening the sealed experiment chamber, and allowing radioactive tail gas to pass through CO₂An absorber, wherein 300ml of 0.2mol/L NaOH solution is arranged in the absorber;

(1.4) starting a high-efficiency ventilation filtering system of the high-illumination artificial climate chamber, and discharging radioactive tail gas;

(2) the tritiated water feeding method comprises the following steps:

(2.1) placing typical crops near the plant site in a sealed experiment cabin;

(2.2) suction with a liquid-feeding gun of 5.6X 10⁴Bq/ml ³Transferring 4.5ml of H source liquid solution into a tritiated water generator, adding 5ml of distilled water, and spraying the generated tritiated water into a sealed experimental cabin to carry out gas-borne nuclide³H in the ecological transfer experiment of crops and the sealed experiment cabin³Total activity of H2.5X 10⁵Bq, activity concentration in air 2.3X 10⁴Bq/m³；

(2.3) airborne nuclides³H is polluted in crops for 24 hoursOpening the sealed experiment chamber, and enabling the radioactive tail gas to pass through a tritium absorber filled with 300g of blue silica gel;

and (2.4) starting a high-efficiency ventilation filtering system of the high-illumination artificial climate chamber, and discharging radioactive tail gas.

Technical Field

The invention relates to evaluation of radiation environment influence of a post-treatment plant, in particular to an airborne nuclide environment migration test¹⁴C、³H source device and method.

Background

The post-treatment plant is a key link of the nuclear fuel cycle industry, at present, China has long-term development in the aspect of engineering technology, but research and technology accumulation in the aspect of environment influence evaluation of the post-treatment plant are less, at present, relevant environment influence evaluation work of the post-treatment plant in China is basically developed by the same method as that of a nuclear power plant, and the plant site characteristics of large tritium emission amount, alpha nuclide emission and the like of the post-treatment plant are not reflected. In order to ensure the environmental safety of the post-treatment plant under the operating state and the accident condition and provide more accurate and reasonable prediction results, the experimental research on the transfer parameters of the key nuclide in the key pathway-ingestion pathway evaluation process of the post-treatment plant under the operating state is urgently needed to be carried out.

¹⁴C and tritium are key species in the gaseous effluent of a work-up plantIn¹⁴C is mainly based on¹⁴CO₂The invention aims to design a source casting method and a source casting device for improving the environmental migration test process of airborne nuclide 14C and tritium, and provides source item guarantee for the environmental transfer parameter test of the airborne nuclide 14C and tritium.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a method for testing the environmental migration of airborne nuclides¹⁴C、³H source device and method for ensuring tritium and¹⁴and C, the ecological transfer research test of various crops is smoothly developed.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

airborne nuclide environmental migration test¹⁴C、³H source device includes:¹⁴CO₂a source device of the tritiated water and a source device of the tritiated water,

the above-mentioned¹⁴CO₂The source device comprises CO₂Reactor, sealed experiment chamber and CO₂An absorber;

will be provided with¹⁴Transfer of radioactive source C to the CO₂In the reactor, CO is produced by reaction₂The generated gas is loaded into a sealed experiment chamber to carry out gas-loading nuclide¹⁴Ecological transfer test of C in crops, airborne nuclide¹⁴C, after the crops are polluted for a first preset time, opening the sealed experiment chamber, and allowing radioactive tail gas to pass through the CO₂Discharging the waste gas after the absorber;

the tritiated water feeding device comprises a tritiated water generator, a sealed experiment cabin and a tritium absorber;

will be provided with³Transferring the radioactive source liquid to the tritiated water generator, reacting to generate tritiated water, and spraying the generated tritiated water into the sealed experiment chamber to carry out gas-borne nuclide³Ecological transfer experiment of H in crops, airborne nuclide³After H is polluted in crops for a second preset time, opening the sealed experiment chamber, and discharging radioactive tail gas after the radioactive tail gas passes through the tritium absorber;

wherein, whole experimental apparatus all places in high illumination artificial climate room, sets up illumination, temperature, humidity automatically, and the experimental parameters of the sealed laboratory of indirect control, after nuclide transfer experiment, the radioactive tail gas of sealed laboratory filters through the high-efficient ventilation filtration system of high illumination artificial climate room, and discharge to reach standard.

Furthermore, according to the device, the frame of the sealed experiment chamber is made of bridge-cut aluminum, the four sides and the top of the sealed experiment chamber are made of glass with good light transmission, and the volume of the sealed experiment chamber is 11m³Bottom area of 5m²。

Further, the apparatus as described above, the CO₂The reactor is a 500ml distillation flask, wherein 0.2mol/L Na is quantitatively added into one bottle mouth₂CO₃Solutions and¹⁴c radioactive source solution, 0.2mol/LH is added in a quantitative manner₂SO₄A magnetic stirrer is arranged at the bottom of the distillation flask, radioactive gas is generated at the other bottle mouth, and the gas is loaded into the first sealed experiment chamber through a polyethylene pipe to carry out gas loading of nuclides¹⁴And C, testing ecological transfer parameters of crops.

Further, the apparatus as described above, the CO₂The absorber is a 500ml conical flask, and after the airborne nuclide ecological transfer test is finished, the radioactive tail gas discharged by the first sealed test chamber is absorbed by adopting a saturated NaOH solution.

Further, according to the device, the tritiated water generator is a compressed air type atomizer, the median diameter of fog particles is 3.9 microns +/-25%, the proportion of the fog particles with the diameter less than 5 microns is more than 65%, the maximum atomization rate is more than or equal to 0.2ml/min, the pressure range is 0.08-0.15 MPa, and the free air flow of a compression pump is more than or equal to 10L/min.

Further, according to the device, the tritium absorber adopts color-changing silica gel to absorb radioactive tail gas.

Airborne nuclide environmental migration test¹⁴C、³The H source casting method comprises the following steps:¹⁴CO₂the method for feeding tritiated water and the method for feeding tritiated water,

(1) the above-mentioned¹⁴CO₂The source casting method comprises the following steps:

(1.1) placing typical crops near a plant site in a sealed experiment cabin;

(1.2) suction with a liquid-feeding gun of 5.5X 10⁴Bq/ml ¹⁴4.5ml of radioactive source solution of C was transferred to CO₂In the reactor, 10ml of 0.2mol/L Na was added₂CO₃Adding 12ml of 0.2mol/L sulfuric acid solution into the solution, reacting to generate CO2, magnetically stirring, and carrying gas into a sealed experiment chamber through a polyethylene tube to carry out gas-carried nuclide¹⁴C in the crop ecological transfer experiment and sealed experiment cabin¹⁴Total activity of C2.5X 10⁵Bq, activity concentration in air 2.2X 10⁴Bq/m³；

(1.3) airborne nuclides¹⁴C, after 24 hours of pollution in crops, opening the sealed experiment chamber, and allowing radioactive tail gas to pass through CO₂An absorber, wherein 300ml of 0.2mol/L NaOH solution is arranged in the absorber;

(1.4) starting a high-efficiency ventilation filtering system of the high-illumination artificial climate chamber, and discharging radioactive tail gas;

(2) the tritiated water feeding method comprises the following steps:

(2.1) placing typical crops near the plant site in a sealed experiment cabin;

(2.2) suction with a liquid-feeding gun of 5.6X 10⁴Bq/ml ³Transferring 4.5ml of H source liquid solution into a tritiated water generator, adding 5ml of distilled water, and spraying the generated tritiated water into a sealed experimental cabin to carry out gas-borne nuclide³H in the ecological transfer experiment of crops and the sealed experiment cabin³Total activity of H2.5X 10⁵Bq, activity concentration in air 2.3X 10⁴Bq/m³；

(2.3) airborne nuclides³After the H is polluted in crops for 24 hours, opening the sealed experiment chamber, and enabling radioactive tail gas to pass through a tritium absorber filled with 300g of blue silica gel;

and (2.4) starting a high-efficiency ventilation filtering system of the high-illumination artificial climate chamber, and discharging radioactive tail gas.

The invention has the beneficial effects that: the invention treats key nuclides tritium and in the gaseous effluent of a plant after simulation¹⁴C chemical form and emission source item characteristics, and the design is improved aiming at airborne nuclide tritium and¹⁴the method and the device for feeding the C ecological environment migration test chamber ensure tritium¹⁴And C, the ecological transfer research test of various crops is smoothly developed.

Drawings

FIG. 1 is a schematic diagram of an embodiment of the present invention¹⁴CO₂The structure of the source device is shown schematically.

In the attached figure, 1-sealed experimental chamber, 2-CO₂Absorber, 3-magnetic stirrer.

Detailed Description

In order to make the technical problems solved, the technical solutions adopted, and the technical effects achieved by the present invention clearer, the technical solutions of the embodiments of the present invention will be further described in detail with reference to the accompanying drawings.

The embodiment of the invention provides a method for testing migration of airborne nuclide in environment¹⁴C、³H source device includes:¹⁴CO₂a source device of (1) and a source device of tritiated water.

In the embodiment of the present invention, the first and second substrates,¹⁴the C radioactive source is Na₂CO₃A radioactive solution.¹⁴CO₂Is released by Na₂CO₃The solution reacts with sulfuric acid to produce CO₂To ensure¹⁴C is released as completely as possible, and Na is stabilized at a certain concentration₂CO₃Diluting the radioactive source with a solution, and reacting with excess sulfuric acid to form¹⁴CO₂And CO₂The generated gas is introduced into the sealed experiment cabin to carry out the experiment.

The experimental setup is shown in figure 1. Whole experimental apparatus places in high illumination artificial climate room, and high illumination artificial climate room can be according to the experiment needs, and automatic setting illumination, temperature, humidity etc. indirectly control the experimental parameters in sealed experiment cabin. After the nuclide transfer experiment is finished, filtering the radioactive tail gas of the sealed experimental cabin through a high-efficiency ventilation filtering system of a phytotron to achieve the emission standard.

In particular, the amount of the solvent to be used,¹⁴CO₂the source device comprises CO₂Reactor, sealed experimental chamber 1 and CO₂Absorber 2 of¹⁴Transfer of radioactive source C to CO₂In the reactor, CO is produced by reaction₂The generated gas is loaded into the sealed experiment chamber 1 to carry out gas-loading nuclide¹⁴Ecological transfer test of C in crops, airborne nuclide¹⁴C, after the crops are polluted for a first preset time, the sealed experimental cabin 1 is opened, and radioactive tail gas passes through CO₂And the absorber 2 is discharged. In particular, CO₂The reactor can be a 500ml distillation flask, wherein 0.2mol/L Na is quantitatively added into one bottle mouth₂CO₃Solutions and¹⁴c radioactive source solution, 0.2mol/LH is added in a quantitative manner₂SO₄A magnetic stirrer is arranged at the bottom of the distillation flask, radioactive gas is generated at the other bottle mouth, and the gas is loaded into the first sealed experiment chamber through a polyethylene pipe to carry out gas loading of nuclides¹⁴And C, testing ecological transfer parameters of crops. In particular, CO₂The absorber can be a 500ml conical flask, and after the airborne nuclide ecological transfer test is finished, the radioactive tail gas discharged by the first sealed test chamber is absorbed by adopting a saturated NaOH solution.

The invention uses stable CO₂Carrier tape¹⁴CO₂Method of (1) in Na₂CO₃(0.2mol/L) solution with H₂SO₄(0.2mol/L) solution, reaction to produce stable CO₂The air-borne source item can fully enter the sealed test chamber, and the air-borne nuclide is ensured¹⁴And C, smoothly performing an ecological transfer test on crops. Whole experimental apparatus places in the high illumination artificial climate room, and tail gas after the experiment discharges smoothly through artificial climate room's high-efficient ventilation filtration system, effectively reduces environmental pollution.

Specifically, the tritiated water feeding device comprises a tritiated water generator, a sealed experiment cabin and a tritium absorber, and the tritiated water feeding device is used for feeding tritiated water³Transferring the radioactive source liquid to a tritiated water generator, reacting to generate tritiated water, and spraying the generated tritiated water into a sealed experimental cabin to carry out gas-borne nuclide³Ecological transfer experiment of H in crops, airborne nuclide³And after the H is polluted in the crops for a second preset time, opening the sealed experiment chamber, and discharging the radioactive tail gas after the radioactive tail gas passes through the tritium absorber. In particular, the tritiated water generator may be a compressed air mistThe medium diameter of the fog particles is 3.9 mu m +/-25 percent, and the proportion of the fog particles with the diameter less than 5 mu m>65 percent, the maximum atomization rate is more than or equal to 0.2ml/min, the pressure range is 0.08-0.15 MPa, and the free air flow of the compression pump is more than or equal to 10L/min. The particles with the particle size less than 10 mu m can stably exist in the air for a long time, and can be used for developing the airborne nuclide ecological transfer experiment. The tritium absorber can adopt allochroic silica gel to absorb radioactive tail gas. Compared with the common tritium water heating source feeding mode, the compressed air type atomizer is directly adopted, the temperature of the sealed test chamber is not changed, and the smooth operation of the ecological transfer test of airborne nuclides in crops is ensured.

The invention arranges the whole source device in a high-illumination artificial climate chamber, ensures that the radioactive tail gas reaches the standard and is discharged by non-Na with certain concentration₂CO₃The solution is used for diluting sodium carbonate radioactive source and reacts with excessive sulfuric acid to generate¹⁴CO₂And CO₂The mixed gas of (2) improves the radioactive source¹⁴CO₂The rate of formation. A compressed air type atomizer is directly adopted in the source of the airborne tritiated water as an atomization source generator of the tritiated water, the particle size and the spraying rate of the spray are selected, the experiment is carried out under the normal temperature condition, and the influence of the temperature on the airborne nuclide ecological transfer experiment is reduced. The invention provides air-borne for nuclide ecological transfer test completely¹⁴C、³The H source item ensures the smooth performance of the evaluation research of the radiation environment influence of the post-treatment plant, and has strong popularization and practical value.

According to another aspect of the embodiment of the invention, the invention also provides a method for testing the environmental migration of airborne nuclide¹⁴C、³The H source casting method comprises the following steps:¹⁴CO₂a method of feeding tritiated water and a method of feeding tritiated water.

(1)¹⁴CO₂Method for implementing the source

By integrating the transfer parameter literature value and the post-treatment plant emission parameter of airborne radionuclide in crops, the airborne radionuclide is developed during the ecological transfer test of crops in a sealed experimental cabin¹⁴Total activity of C2.5X 10⁵Bq, activity concentration in air 2.2X 10⁴Bq/m³。

Firstly, typical crops (such as eggplants and leaf lettuce) near a plant site are placed in a sealed experimental cabin.

Suction of 5.5X 10 using a liquid-dispensing gun⁴Bq/ml ¹⁴C radioactive source liquid 4.5ml (existing form Na)₂CO₃Solution), transfer to CO₂In the reactor, 10ml of 0.2mol/LNa was added₂CO₃Adding 12ml of 0.2mol/L sulfuric acid solution into the solution, and reacting to generate CO₂The magnetic stirrer stirs, and the gas is loaded into a sealed experiment chamber through a polyethylene pipe¹⁴Total activity of C2.5X 10⁵Bq, activity concentration in air 2.2X 10⁴Bq/m³And performing an ecological transfer experiment of the airborne nuclide in crops.

After airborne nuclides are polluted in crops for 24 hours, the sealed experiment chamber is opened, and tail gas passes through CO₂Absorber, absorber is 0.2mol/L NaOH solution 300 ml.

And starting a high-efficiency ventilation and filtration system of the high-illumination artificial climate chamber, and discharging radioactive tail gas.

(2) Method for specifically implementing source feeding of tritiated water

Air-borne nuclide during development of ecological transfer test of crops in sealed experimental cabin³Total activity of H2.5X 10⁵Bq, activity concentration in air 2.3X 10⁴Bq/m³。

Suction of 5.6X 10 using a liquid-dispensing gun⁴Bq/ml ³The volume of the H source solution is 4.5ml (HTO solution), the solution is transferred to a sample cup of a sprayer, 5ml of distilled water is added, and the tritiated water atomization rate is increased. The product is used for spraying in a sealed cabin, and the median particle size of the atomized particles is 3.9 mu m.³Total activity of H2.5X 10⁵Bq, activity concentration in air 2.3X 10⁴Bq/m³。

After airborne nuclides are polluted in crops for 24 hours, the sealed experiment chamber is opened, and radioactive tail gas passes through a tritium tail gas absorber filled with 300g of blue silica gel.

And starting a high-efficiency ventilation and filtration system of the high-illumination artificial climate chamber, and discharging radioactive tail gas.

The inventionTreatment of key species tritium and in the gaseous effluent of a plant in a simulated aftertreatment¹⁴C chemical form and emission source item characteristics, and the design is improved aiming at airborne nuclide tritium and¹⁴the method and the device for feeding the C ecological environment migration test chamber ensure tritium¹⁴And C, the ecological transfer research test of various crops is smoothly developed.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is intended to include such modifications and variations.